This invention relates generally to the field of vehicular power conversion. More particularly, it concerns improved efficiency in the provision of auxiliary power conversion systems for marine, recreational, commercial, air and/or military crafts or vehicles.
American commercial truckers are required by recent federal regulation to pull off the highway and rest for ten hours out of every twenty-one hours on the road, e.g. eleven hours of driving must be followed by ten hours of rest. To date, truckers have pulled over and idled their truck engines during such stops, thereby to produce power sufficient to continuously or periodically operate air conditioning/heating and appliances such as refrigerators, televisions, computers, etc.
Internal combustion engines are extremely inefficient when idling. Children's asthma symptoms increase as a result of vehicle exhaust. The smallest pollutants from vehicle exhaust lodge deeply in the lungs causing lung damage, aggravating respiratory conditions such as asthma and bronchitis, increasing the risk of stroke and heart attack, leading to cancer and contributing to premature death. Vehicle exhaust is the leading source (˜40-50%) of toxic air pollution in Oregon. Idling vehicles emit significant amounts of pollution, including sulfur dioxides, carbon monoxide, nitrogen oxide, and volatile particulate organic compounds leading to the formation of atmospheric carbon dioxide (CO2). All known, peer-reviewed, published scientific studies agree that carbon dioxide by-products of human manufacture are a major contributor to global warming. An idling vehicle engine delivers zero miles to the gallon and thus wastes fuel, e.g. gasoline, diesel, bio-diesel or the like. Excessive idling is hard on a vehicle engine because the engine does not idle at peak operating temperature. Fuel does not undergo complete combustion, leaving spark plugs dirty, damaging cylinders and exhaust systems, and contaminating engine oil. Thus, such roadside idling to conform with the new federal safety regulations represents an inefficient and potentially damaging tax on a vehicle's engine, a waste of increasingly depleted fossil-fuel-based vehicle fuel resources worldwide, and an emission plume of air-borne toxins that harm the atmosphere and worsen an already existing global health hazard.
(A commercial trucker can drive only seventy hours in an eight day period, with a minimum of thirty-four hours of rest before restarting a fresh seventy hours. Accordingly, a typical driver idles approximately one hundred hours each week, and thus spends approximately four hundred hours per month idling. At approximately $3/gallon of diesel, this represents approximately $1200 dollars per month of wasted diesel, a precious fossil fuel commodity. The cost of running a conventional auxiliary power unit (APU) is approximately $400 dollars per month, at a cost savings (over idling the commercial truck's main internal combustion engine) of approximately $800 per month or $10,000 per year per commercial truck, based upon current fuel prices. The higher the price and scarcity of fuel, the more savings monthly, e.g. annually the trucker and/or company saves. Nevertheless, conventional APUs are relatively inefficient and costly to operate as an alternative to idling the main engine.)
Recreational vehicles (RVs), buses, houseboats, yachts, and other land or marine craft including military craft have auxiliary power needs similar to those of the commercial trucker for supplying power to such auxiliary systems as air conditioners/heaters and appliances such as refrigerators, computers, navigational or communication equipment, radios and the like. Many such appliances, e.g. televisions, require one or more relatively clean sources of alternating current (AC) power.
Refrigerated commercial trucks (so-called “refers”) require an even more robust source of AC power. The power needs of such specially equipped trucks deeply tap the generator connected to the main drive system for the truck, i.e. its internal combustion engine. Conventional APUs do not supply sufficient power to meet such stringent refrigeration needs.
Finally, so-called “daycabs” having no sleepers and thus no extra cargo capacity nevertheless require auxiliary power for frequent stops made typically to load or unload cargo such as spoilable foodstuffs from or to restaurants. Such stops are relatively brief, e.g. 10-20 minutes, but are frequent, e.g. every ½-1 hour. Because of emissions and conservation laws in many jurisdictions, as well as costs, idling such daycabs to provide HVAC auxiliary power during such stops is not feasible. As a result, during such stops, the cab heats up in the summer or cools off in the winter, making for uncomfortable frequent returns by the driver to the daycab.
Accordingly, there is a need to provide clean and robust HVAC power to such auxiliary systems and appliances and at the same time to reduce the rate of consumption and pollution caused by roadside idling of land- and marine-based internal combustion engines.